LG2A

Laboratoire de Glycochimie, des Antimicrobiens
et des Agroressources UMR 7378 CNRS

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  • Tutelle du CNRS
  • Tutelle UPJV

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Actualités et Publications

Highly Water-Soluble Amphiphilic Cyclodextrins Bearing Branched and Cyclic Oleic Grafts,

Cocq, A.; Rousseau, C.; Bricout, H.; Oliva, E.; Bonnet, V.; Djedaïni-Pilard, F.; Monflier, E.; Tilloy, S.

Eur. J. Org. Chem. 0.

Amphiphilic β-cyclodextrins bearing various amounts of branched and cyclic oleic grafts are synthetized. The first step of this synthesis is the alkenylation of maleic anhydride by oleic acid derivatives, in the presence of a rhodium catalyst, to produce oleic succinic anhydrides with different ratios of cyclic to branched groups. The second step is the grafting of the oleic succinic anhydrides mixtures on β-cyclodextrin. The obtained cyclodextrins are highly water-soluble and surface active.

Concours i-Lab 2019 : Le LG2A récompensé

Porteur du projet : Franck Barath; Chercheurs associés : Frédéric Sauvage (LRCS) et Albert Nguyen Van Nhien (LG2A)

Catégorie CHIMIE ET ENVIRONNEMENT

G+Lyte: nouveaux électrolytes ultrastables à haut rendement pour les cellules photovoltaïques à colorant G+Lyte a créé 3 nouvelles générations d’électrolytes pour les cellules photovoltaïques à colorant. Cette technologie dite de troisième génération est parmi les plus prometteuses pour le smartgrid, l’électronique nomade et la mobilité électrique. Les cellules à colorant sont particulièrement performantes en luminosité dégradée (pollution, intérieur, exposition non directe, etc.). Simple et peu exigeante par rapport aux panneaux silicium, leur production est favorable en terme d’empreinte carbone et peut être localisée en Europe.
La création de la société est prévue pour l’été 2019 et la ligne pilote permettra la production de plus de 1 000 m2 de panneaux la première année ainsi que la réalisation de tests de vieillissement accélérés pour la mise au point des solutions d’électrolytes.

Uncommon Strong Inhibition of α-Glucosidase by Multivalent Glycoclusters built on Cyclodextrins Scaffolds,

Alali, U.; Vallin, A.; Bil, A.; Khanchouche, T.; Mathiron, D.; Przybylski, C.; Beaulieu, R. R.; Kovensky, J.; Benazza, M.; Bonnet, V.

Org. Biomol. Chem. 2019.

The homeostasis disruption of D-glucose causes diabetes, a dramatic world wide chronic disease. The type 1 diabetes is a succesfully treatable form, where the blood D-glucose is regulated by insulin treatement. In contrast the type 2 diabetes , the non Insulin dependent one, is problematic. The control of the D-glucose blood level via intestinal α-D-glucosidase inactivation can be achieved by using competitive inhibitors as iminosugars (e.g. acarbose) or sulfonium sugar derivatives (e.g. salacinol). Recently, an unprecedented result showed that multivalent diamond nanoparticules grafted with unmodified sugars displayed α-glucosidase inhibition at low micromolar concentrations. We describe herein the synthesis of multivalent glycoclusters using cyclodextrines (CDs) as scaffolds and their assessment as inhibithors of α-D-glucosidase. The glycoclusters were efficiently obtained from per-azido α, β and γ-CDs derivatives and propargyl glycosides using click-chemistry under microwave irradiation. The methodology was successfully applied to various protected and non-protected propargylated monosaccharides, including both O- and S- glycosides, giving clear evidences of its versatility. The targeted 6-per-glycosylated CDs were isolated in moderate to excellent yields (30-90 %) by silica gel chromatography. The results showed inhibition of α-glucosidase from Saccharomyces cerevisiae with IC50 values in a 32-132 µM range, lower than that of acarbose (IC50 ~250µM), a well knowm competitive inhibitor used in clinical treatment of type 2 diabetes. Preliminary experiments suggest a mixed-type non-competitive inhibition mode of these new glycoclusters.

Ironing out pyoverdine’s chromophore structure: serendipity or design?,

Cézard, C.; Sonnet, P.; Bouvier, B.

JBIC Journal of Biological Inorganic Chemistry 2019.

Pyoverdines are Pseudomonas aeruginosa’s primary siderophores. These molecules, composed of a fluorescent chromophore attached to a peptide chain of 6–14 amino acids, are synthesized by the bacterium to scavenge iron (essential to its survival and growth) from its environment. Hijacking the siderophore pathway to use pyoverdine–antibiotic compounds in a Trojan horse approach has shown promise but remains very challenging because of the synthetic efforts involved. Indeed, both possible approaches (grafting an antibiotic on pyoverdine harvested from Pseudomonas or designing a total synthesis route) are costly, time-consuming and low-yield tasks. Designing comparatively simple analogs featuring the salient properties of the original siderophore is thus crucial for the conception of novel antibiotics to fight bacterial resistance. In this work, we focus on the replacement of the pyoverdine chromophore, a major roadblock on the synthetic pathway. We propose three simpler analogs and evaluate their ability to complex iron and interact with the FpvA transporter using molecular modeling techniques. Based on these results, we discuss the role of the native chromophore’s main features (polycyclicity, positive charge, flexibility) on pyoverdine’s ability to bind iron and be recognized by membrane transporter FpvA and propose guidelines for the design of effective synthetic siderophores.

Synthesis of multivalent S-glycosides analogs of a heparan sulfate sequence,

Koffi Teki, D. S.-E.; Bil, A.; Moreau, V.; Chagnault, V.; Fanté, B.; adjou, a.; Kovensky, J.

Organic Chemistry Frontiers 2019.

Glycosaminoglycans (GAGs) are involved in the regulation of a large number of biological processes such as inflammation, cell signalling, angiogenesis, viral infection and coagulation. Unlike molecules isolated from tissues, pure molecules, derived from organic synthesis, can prevent side effects and are very useful tools for understanding the structure-activity relationships of many biological and pharmacological activities. In our research group, we focus particularly on the synthesis of multivalent thioglycoside analogs. In this article, we report the synthesis of new glycoclusters with thiodisaccharide units, S-analogs of heparan sulfate. The thiodisaccharide analog was obtained by nucleophilic displacement of a 4-triflate galactoside derivative, by an anomeric thiol of a glucuronic acid precursor. After modifying the aglycone part to introduce an azide, the thiodisaccharide was coupled to maltotriose scaffolds carrying one, two or three propargyl groups by CuAAC.

Impact of the chemical structure on amphiphilic properties of sugar-based surfactants: A literature overview,

Gaudin, T.; Lu, H.; Fayet, G.; Berthauld-Drelich, A.; Rotureau, P.; Pourceau, G.; Wadouachi, A.; Van Hecke, E.; Nesterenko, A.; Pezron, I.

Adv. Colloid Interface Sci. 2019, 270, 87-100.

In this review, structure-property trends are systematically analyzed for four amphiphilic properties of sugar-based surfactants: critical micelle concentration (CMC), its associated surface tension (γCMC), efficiency (pC20) and Krafft temperature (TK). First, the impact on amphiphilic properties of the alkyl chain size and the presence of branching and/or unsaturation is investigated. Then, various polar head parameters are explored, such as the degree of polymerization of the sugar unit (mono- or oligosaccharides), the chemical nature of the linker and the sugar configuration. Some systematic comparisons between ethoxylated surfactants and sugar-based surfactants are also carried out. While some structural trends with the impact of alkyl chain length or the polar head size are now well understood, this analysis points out that systematic studies of more specific effects of alkyl chain (e.g. branching, unsaturation, presence of rings, position on the polar head) and polar head (e.g. linker, anomeric configuration, internal stereochemistry, cyclic vs. acyclic sugar residues) were scarcer or not available to date. This work encourages the use of these structural trends in the perspective of developing new bio-based surfactants and their consideration in predictive models. It also highlights the need of further experimental tests to fill remaining gaps notably to explore some specific structural features (such as the introduction of rings in the alkyl chain or the position of the alkyl chain on the polar head) and towards applicative properties (like foaming capacity or wettability).



Laboratoire de Glycochimie, des Antimicrobiens et des Agroressources
UMR 7378 CNRS
10 rue Baudelocque
80039 Amiens Cedex
tel/fax : 33 (0)3 22 82 75 60
N° SIRET : 19801344300017